Worker Killed During Brake Test

One worker was killed and two others were injured when a defective brake caliper, designed to fit heavy mining equipment, exploded during a test.

The victim had hooked up a bottle of compressed oxygen to pressurize the caliper and was checking for possible leaking gaskets when the explosion occurred. WorkSafeNB’s investigation revealed that the oxygen reacted with residue of hydraulic brake fluid in the caliper that turned it into a pipe bomb. Flying fragments killed the man on the spot, and his co-workers had to be taken to the hospital.

Recommended Preventive Action

  • Compressed oxygen should never be used in the presence of oily or greasy substances, as they can ignite spontaneously and burn vigorously without warning.
  • Controlled hydraulic pressure should be used to test components like the brake caliper under pressure, whenever possible, and supervisors and workers should be informed of the hazards involved when doing such testing.
  • Employers must ensure employees who work with, or in proximity to, a controlled product such as compressed oxygen are informed of all the hazards associated with its use, and instructed in the safe use of the controlled product by providing training in the Workplace Hazardous Materials Information System (WHMIS).
  • READ LABELS and heed the warnings. All containers of compressed oxygen are clearly marked with warnings about the dangers of mixing it with any greasy or oily substance.

Revised September 2011

1 800 222-9775